The present invention relates generally to an article stock closet, and more particularly to an improvement in a rotatable stock container closet including a plurality of open containers for the storage of articles such as electronic parts, or the like, movably arranged in a plurality of container conveying units arranged vertically one on another.
The typical design of a conventional stock container closet of movable type including a plurality of movable open containers is such that each of the containers is carried by four free-running wheels on and along a pair of outer and inner rails disposed in parallel with each other, two wheels each on each of the outer and inner rails, respectively. With such construction, when the container runs along a curved section of the rail, it is observed that these wheels are forced to turn along the curvature of the rail, each wheel on the outer side differing in its running direction and rotation number from those characteristics of each wheel on the inner side, causing the wheels on the outer side to continuously slip slightly sideways off their original running direction while passing through the curved section, thus resulting in such an adverse effect that the container wheels are likely to be worn due to such forced slipping motion and the container is subjected to a substantial resistance in the running operation. The terms "outer" and "inner" as used herein are defined to mean the outside and inside as viewed from the central portion of the frame structure of the stock container closet having the general-construction as shown in FIG. 1, respectively.
On the other hand, after a long time use of a stock container closet of the type mentioned above, it is inevitable that the joints or connected points of an endless pull or traction chain would get worn so that the total extension or loop of the chain would thus become longer, which would very possibly spoil a smooth running operation of the chain along the guide rails, eventually causing such trouble that the containers would run out of their tracks.
In this respect, it has been the practice that two shafts for the chain driving sprockets are preliminarily provided with an adjustability in the span or distance across their axes outwardly to a desired extent so that a possible slack due to wear of the chain may adjustably be absorbed, and at the same time the guide rails are provided with split parts near their ends on one side or on opposite sides of the straight sections thereof opposedly adjacent the curved sections thereof so that the split parts may adjustably be slid away from the straight ends of the principal rail portion to extend the total stretch or length of the straight sections of the rails to such an extent that would correspond to the distance of axial adjustment of the sprocket shaft for due compensation for the amount of slack on the driving chain, while thus formed gap or gaps between the extended split parts and the straight ends of the principal rail portions may be filled up with a filler plate or plates so as to form a smooth continuation of the rails where so connected.
For this purpose, there are required a variety of filler plates having many different sizes and enough to cover such gaps as are formed from the axial adjustment of the sprocket shaft or shafts, which would naturally mean a troublesome job requiring substantial time and labor.
The present invention is essentially directed to meet such inconveniences and drawbacks which have not been attended with satisfactory results.